(notes taken from the CGP revision guides)
- Analogue signals vary but digital's either on or off.
- The amplitude or frequency of an analgue signal vary continuously.
- An analogue signal can take any value in a particular range.
- Dimmer switches, thermometers, speedometers and old-fashioned watches are all analogue devices.
- Digital signals can only take two values - they're made up of 'pulses'.
- A digital receiver will decode these pulses to get a copy of the orignal signal.
- On/off switches and the displays on digital clocks and meters are all digital devices.
- Signals have to be amplified.
- Both digital and analogue signals weaken as they travel, so they may nee to…